Israel's military warned Gaza residents that it would stop any breach of its border fence and that those approaching it in a planned mass protest would be putting their lives in danger.
Gaza's Hamas rulers said tens of thousands were expected to head to the border overnight and raised the possibility of large crowds breaking through the fence.
The overnight march was part of a weeks-long campaign, led by Hamas and fuelled by despair among Gaza's 2 million people, to break the decade-old border blockade of the territory by Israel and Egypt.
Since weekly border marches began in late March, 42 Palestinian protesters have been killed and more than 1800 wounded by Israeli army fire.
Leaflets dropped over Gaza by army jets warned that those approaching the border "jeopardise" their lives. The warning said the army was "prepared to face all scenarios and will act against every attempt to damage the security fence or harm IDF soldiers or Israeli civilians".
